This study is an open-label, multi-center, Phase 2 study investigating the use of Flt3 Ligand via subcutaneous (SC) injection to treat patients with metastatic melanoma. Patients with previously untreated metastatic disease (slow growing, small volume) and those who have failed one prior treatment regimen for matastatic disease will be eligible for this study. The study's objectives are to evaluate the safety and efficacy of Flt3L as an immunotherapy agent in patients with metastatic melanoma. 30-40 patients will enter the study nationwide; 10 will be enrolled through the University of Pittsburgh Cancer Institute (UPCI). Patients will receive a daily SC dose of 25ug/kg of Flt3L for 14 consecutive days, for 6 cycles. Each cycle will consist of 28 days. All patients who receive at least one dose of study drug will be evaluated for safety. All patients who receive two cycles of study drug with two weeks of follow up (8 weeks on study) will be evaluated for tumor response. All patients who receive at least one cycle (14 days) of study drug with two weeks of follow up (4 weeks on study) will be evaluated for immunologic activity.